AJP - Regulatory, Integrative and Comparative Physiology, Vol 259, Issue 1 70-R75, Copyright © 1990 by American Physiological Society
Mechanisms of impaired excretion of a fluid load after cardiac denervation in dogs
T. D. Williams, C. M. Travill, M. I. Noble, A. J. Drake-Holland, J. Chalmers, C. D. Jeffery, R. Sutton and S. L. Lightman
Department of Medicine, Charing Cross and Westminster Medical School, London, United Kingdom.
The influence of cardiac innervation on the renal response to volume
expansion was investigated. Systemic hemodynamic, plasma hormone, and renal
clearance measurements were made before, during, and after intravenous
administration of 1,000 ml 0.9% saline over 10 min to six control and six
cardiac-denervated, chloralose-anesthetized mongrel dogs. Volume expansion
resulted in a two- to threefold rise in plasma atrial natriuretic peptide
(ANP) concentrations and a 50% rise in glomerular filtration rate (GFR) in
both groups. Plasma renin activity (PRA) and plasma arginine vasopressin
remained higher throughout in cardiac-denervated compared with control
dogs. The marked increases in urine flow rate and sodium and free water
clearances seen in the controls were attenuated or abolished after cardiac
denervation. These differences were due to the influence of higher PRA and
vasopressin in these animals compared with the controls, rather than
differences in hemodynamic responses operating via GFR or in direct humoral
responses via ANP secretion.
